title: Developmental and physiological challenges of octopus (Octopus vulgaris) early life stages under ocean warming.
abstract: The ability to understand and predict the effects of ocean warming (under realistic scenarios) on marine biota is of paramount importance, especially at the most vulnerable early life stages. Here we investigated the impact of predicted environmental warming (+3 °C) on the development, metabolism, heat shock response and antioxidant defense mechanisms of the early stages of the common octopus, Octopus vulgaris. As expected, warming shortened embryonic developmental time by 13 days, from 38 days at 18 °C to 25 days at 21 °C. Concomitantly, survival decreased significantly (~29.9 %). Size at hatching varied inversely with temperature, and the percentage of smaller premature paralarvae increased drastically, from 0 % at 18 °C to 17.8 % at 21 °C. The metabolic costs of the transition from an encapsulated embryo to a free planktonic form increased significantly with warming, and HSP70 concentrations and glutathione S-transferase activity levels were significantly magnified from late embryonic to paralarval stages. Yet, despite the presence of effective antioxidant defense mechanisms, ocean warming led to an augmentation of malondialdehyde levels (an indicative of enhanced ROS action), a process considered to be one of the most frequent cellular injury mechanisms. Thus, the present study provides clues about how the magnitude and rate of ocean warming will challenge the buffering capacities of octopus embryos and hatchlings' physiology. The prediction and understanding of the biochemical and physiological responses to warmer temperatures (under realistic scenarios) is crucial for the management of highly commercial and ecologically important species, such as O. vulgaris.
authors.affiliation: Laboratório Marítimo da Guia, Centro de Oceanografia, Faculdade de Ciências da Universidade de Lisboa, Av. Nossa Senhora do Cabo, 939, 2750-374, Cascais, Portugal.
authors.forename: Tiago
authors.initials: T
authors.lastname: Repolho
authors.forename: Miguel
authors.initials: M
authors.lastname: Baptista
authors.forename: Marta S
authors.initials: MS
authors.lastname: Pimentel
authors.forename: Gisela
authors.initials: G
authors.lastname: Dionísio
authors.forename: Katja
authors.initials: K
authors.lastname: Trübenbach
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: Lopes
authors.forename: Ana Rita
authors.initials: AR
authors.lastname: Lopes
authors.forename: Ricardo
authors.initials: R
authors.lastname: Calado
authors.forename: Mário
authors.initials: M
authors.lastname: Diniz
authors.forename: Rui
authors.initials: R
authors.lastname: Rosa
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000502:physiology*; D047108:Embryonic Development; D057232:Global Warming; D005982:Glutathione Transferase / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D015227:Lipid Peroxidation; D008315:Malondialdehyde / Q000378:metabolism; D009792:Oceans and Seas; D049831:Octopodiformes / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism
chemical_list: D018840:HSP70 Heat-Shock Proteins; D008315:Malondialdehyde; D005982:Glutathione Transferase; D010100:Oxygen